I got myself a spunky Samsung Galaxy Tab (GT-P1010) 7" tablet (no service plan, just the plain, off the shelf edition) about two months ago and have been puzzled by its slow charging time. I usually take note of how long lengthy processes take, such as charging my mobile devices (cellphones, laptop) or running hard disk diagnostics, so I could easily set a 'deadline' for when I'm gonna have to tend to that device again (say, plugging it off).

Anyway, I thought I already nailed down the time it takes my Tab to recharge, which was 3.5 hours one time (yes, only one time) off the power outlet (I never charge via USB), but I guess that was off. I had a hunch the battery level reported when pressing the power button when the device is off is wrong, and perhaps 2.5 hours was actually enough to fill 'er up. I tried it today, charging the device at 12% battery level for 2.5 hours. After that duration the battery was just at 50%. I usually charge the device overnight while I sleep so it's ready the next morning but I have no idea how long it took to reach 100%. Extrapolating from 2.5 hours to get the battery from 12% to 50% will give us something like 6.5 hours. That's a pretty long time to recharge.

I've been looking all over the Net for information on how other users' experiences have been regarding charging the GT-P1000 / GT-P1010 (no 3G variant), and I came across this article at PC World saying the thing takes long to recharge. But how long is long?

You have also to take into account that battery voltage curve / OS battery charge display / battery behavior are not linear mathematical relations. Charging the battery 1 hour to 50% doesn't mean that it takes 2 for it to go 100%, etc etc. Also, OSes will sometimes present "softer" battery capacity maps, allowing the OS to display on screen 100%, 90%, 80% "battery left" when in fact, it's actually lower, etc etc.

In real life it actually takes longer for a battery to REALLY charge all they way up to 100% from 90%, than it takes for it to charge from 80% to 90%, 70% to 80% and so forth.

Example Charge Curve:

Example Discharge Curve:Most important is the actual battery capacity in mAh and the charger capacity for providing power to charge the battery fast enough. With good charging practices, I'd say your device is doing fine.